The purpose of this work is to study translation of the RNA of representative members of an important group of viruses--the group whose genetic material is messenger RNA. We will use the RNAs of brome mosaic virus, RNA phage, EMC virus and Rous sarcoma virus as messengers in a cell-free protein synthesizing system derived from wheat embryo. By biochemical and other analyses we want to determine what information is encoded in the RNA of these viruses and what are the regulating factors involved in their translation.